Need help with a Tortoise Switch Machine

[jonathan]

I am ready to start changing out my Atlas switch machines for the Tortoise machines.  I have one to start for learning purposes.

I believe I have figured out the assembly and wiring of the switching portion.  However, I am a little confused on the other wiring tabs.  I understand tabs 1 and 8 are for the motor.  I can use a DPDT to change direction/polarity.

I want to connect alternating lights to tabs 2 thru 7 so I can tell which way the switch is thrown at a distance.  The included diagram is over my head.  It appears tabs 2-4 and 5-7 somehow interact with each other.

Can anyone give me a clue?  

Regards,

Jonathan

[Joe Satnik]

Dear Jon,

According to Tony, you don't need the two Tortoise SPDT switches to indicate turnout points direction:

http://tonystrains.com/technews/archive/circuitron.htm

(Scroll to bottom.)

From Wiki:

"Bi-color LEDs are actually two different LEDs in one case. They consist of two dies connected to the same two leads antiparallel to each other. Current flow in one direction emits one color, and current in the opposite direction emits the other color."

I'm guessing that this Radio Shack 276-012 is one:

http://www.radioshack.com/product/index.jsp?productId=2062549

Simply wire a single bi-color LED in series (in line) with pin 1 of the Tortoise machine.  

Swap the leads on the bi-color LED if the points move the opposite that the LED indicates.

Polarity switch
outputs 1 and 2:


O1 -----------------------L1 LED L2--------------P1 Tortoise machine P8-----l
Polarity                                                                                                 l
Switch                                                                                                  l
O2--------------------------------------------------------------------------l


The Tortoise machine itself is the "current limiting resistor" for the Bi-color LED.

Hope this helps.

Sincerely,

Joe Satnik

Edit:  Added "The Tortoise machine itself....", capitalization

[Joe Satnik]

Dear Jon,

Page 2 of this pdf shows the internal diagram of the Tortoise machine, including the Auxiliary Contacts.

http://www.dccspecialties.com/products/pdf/man-hare-draft.pdf 

I had to go to a different website than Circuitron to find it.

Don't know if the positions of the internal switches shown in the diagram are for "pin 1+ pin 8-", or for "pin 1- pin 8+".

Note that those SPDT switches (or, any switch, for that matter) have current and voltage limits, which I haven't run across yet.

Hope this helps.

Sincerely,

Joe Satnik   

[jonathan]

Joe,

Thanks for that info.  I saved the link to my favorites.

I like the simplicity in the design.  I could set a single led to be on when the switch is closed, to warn me the way is not clear for an approaching train.  Will probably mount the light on my facia, right in front of the turnout, facing my control station. 

I will try it with an extra led I have lying around here somewhere.

You da man.

Regards,

Jonathan

[jward]

note:
an led is a diode. it only passes electric current one way. to use an led with a tortoise, you'd need two of them, connected together in opposite polarities. this is what a bi-colour led is, two leds connected in ppposite polarities, in one package. using a regular led by itself in series with the tortiose means the tortoise will only throw one way.......

[jonathan]

I was thinking along those lines.  Couldn't I use a 'bridge' (extra piece of wire) so the current will still flow, even when the led is not lit?

I'm still a little green when it comes to electrical matters.

Regards,

Jonathan

[jward]

no. if you"bridge" the led with a wire, all current will bypass the led and it will not light. that is known as a partial short circuit. electricity tries to take the path of least resistance.

here's an idea for you. if you are going to use an led as a panel light why not use one for each route of the switch. i am assumung you have the track diagram drawn on your control panel. if so, you can use two leds so that only the route the switch is set for will light up. the wiring diagram included with the tortoise shows how to do this.

[Joe Satnik]

Dear All,

In both circuits, the electrons see the same thing.  In one direction, the red LED shines.  In the other, the green LED shines.  

Your LED choices are:

1.) Simple wiring/one package (my diagram above), or

2.) Not as simple wiring, 2 packages (Tony's diagram above).

If you want 2 separate LEDs, then use choice 2.  This allows you to choose different colors than red/green.   

Hope this helps.

Sincerely,

Joe Satnik

Edit: Added (my..), (Tony's...), This allows...

[jonathan]

Thanks,

I'm starting to catch on.  Looks like the bi-color led would be the best choice in my case. 

No short cuts (or short circuits) allowed on this project.

Appreciate the education, gentlemen.

Regards,

Jonathan

[Jim Banner]

When using Joe's circuit above, you also have the option of connecting two or three bicolour LEDs in series with the Tortoise motor.  Then you can have indicator lights in more than one place.  For example, one on the panel, one of the ground near the turnout itself.  Or you can make some simple signal masts to mount the LEDs in.  This link shows one way to make such masts:
http://members.shaw.ca/the.trainman/LV_Workshop/signals/plastic/index.html

Adding extra LEDs in series means you will have to have a bit higher voltage to drive them.  For each additional LED, you can add about 3 volts dc.

There is an even better way to operate multiple LEDs.  That is to use one half of a DPDT switch to operate the tortoise motor and the other half to operate the LEDs, as many LEDs as you want.  The neat thing about this is that with a couple of extra cheap components you can also use this setup to operate twin coil switch machines as well.  This means you can have operating signals even before you change over to Tortoise motors and will have to make only a minor adjustment when you replace your dual coil machines with Tortoises.

I don't presently have a wiring diagram in digital form but if anyone is interested, let me know and I will draw you one.



The signal in the foreground of the photo below is similar to what I mentioned above but is made of brass instead of styrene.  The 5 mm LEDs are oversize for H0 but they are easy to see from the side as well as the front.  Alternately, smaller LEDs could be used but would be harder to read from the sides.



Jim

[jonathan]

Thanks, Jim.

As always, you provided a wealth of information that has given me some great ideas with which to work.

On a side note:  I temporarily wired the tortoise to a DC pack I use to run the lights.  When I change direction on the pack (change polarity), the switch operates.  The brighter I turn up the lights, the faster the machine works.  This is a great set up until I get the chance to wire, and light, the machine properly.  

Regards,

Jonathan

[Joe Satnik]

Greetings, All.

Got a reply back from Steve Worack, Technical Support, at Circuitron on the Tortoise auxiliary contacts (SPDT x 2).

"...with -minus on pin 1 and +plus on pin 8, the TORTOISE runs to the left as you face the moving arm. 

In that stalled position, pin 4 is connected to 3 and pin 5 is connected to 7, as is shown in Figure 2 on our instruction sheet.

Reversing polarity on 1 and 8 (P1+ and P8-) will run the TORTOISE to the right and pin 4 will connect to 2 and pin 5 will connect to 6.

There is a small dead area right at the center of the throw, that is, the contacts are break before make in design."

In short, auxiliary SPDT x2 end of travel connections:

P1- and P8+,  4 to 3 and 5 to 7.

P1+ and P8-,  4 to 2 and 5 to 6.

On the switch contact ratings and durability:

"The contacts are rated to SWITCH 1 amp of

current for a minimum of 250,000 operations. They will CARRY quite a

bit more current, typically 5 amps or so. Since it is rare to operate

the turnout while a heavy load is being powered, you should have not

problem. Many, many O scale layouts use the contacts for frog switching

without a problem."

Italics and bold added.

Hope this helps.

Sincerely,

Joe Satnik

[jonathan]

Thanks, Joe.

That helps alot, and gives me further options when I concentrate on my turnout and signalling project in the future.

I copied your info and made a hard copy for my binder.  I was having a hard time making sense of their diagram.

Regards,

Jonathan

[jonathan]

Just an update for those that have been so helpful.

I have successfully wired the switch machine to a DPDT switch and a bicolor, red/green led, which sits in my control area.  Got the polarity correct so the light is red when the switch is thrown for the spur; and the light is green when the switch is thrown for thru travel.  So far, so good.  Thanks, again.  I love it when things work.

I also have a Tomar target signal with red/yellow/green led's.  They share a common wire (+).  I am still trying to decipher how to wire this.  I really want to use the aux poles on the tortoise so I can control the color aspects by throwing the switch.  So far, I have been unable to get the leds to light up on the signal.  Will keep at it.  Thanks, again.

Regards,

Jonathan

[jward]

i love it when a plan comes together.......